Liquid measuring device



Feb. 14, 1939. c. A. LONG 2,147,048

LIQ UID MEASURING DEVICE.

Filed June 29, 1937 2 Sheets-Sheet l I J6 INVENTOR Charles A. Long Feb. 14, 1939. I c, A LONG 2,147,048

L'IQUID MEASURING DEVICE Fil ed June 29, 1937 2 Sheets-Sheet 2 INVENTOR Charles/4. Long i aqz MJM Patented Feb. 14, 1939 UNITED, STATES LIQUID MEASURING DEVICE Charles A. Long, Oakmont, Pa, assilnor to Blaw- Knox Company, Pittsburgh, Pa., a corporation of New Jersey Application June 29. 1937, Serial No. 150,898

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This invention relates to an apparatus and method for measuring liquid. A specific application, in connection with which the invention will be illustrated and described in detail, is the measurement of water for mixing batches of concrete, although the invention has other applications.

In the mixing and handling of concrete, socalled truck mixers" have come into wide use. With such equipment, the dry materials to be mixed are stored at a central point and measured into the mixer. The truck on which the mixer is mounted is then driven to the point where the concrete is to be delivered. The dry materials are mixed with water enroute, but since the length of the trip only rarely corresponds.

precisely to the optimum mixing time, the water must be added to the dry materials at some point between the beginning and end of the trip. The amount of water must, of course, be accurately measured. The proper amount of water may be measured by filling a storage tank to a predetermined level and discharging all the water into the mixer at the proper time. If this is done, however, a separatetank must be provided for carrying water to wash out the mixer when it hasdischarged its contents. This is undesirable from the standpoint of cost and complexity of construction.

It is an object of this invention to provide means for accurately measuring a quantity of liquid from a body thereof while being transported, with such accuracy as is normally required in mixing concrete.

out of a tank until it falls to a predetermined level, because of the disturbance of the surface of the water resulting from the movement of the truck.

vents any disturbance on the surface of the water from! affecting the accuracy of measurement. A vent is provided in the weir chamber to avoid siphoning,

A complete understanding of the invention may preferred embodiment.

This accuracy, of course, can not be obtained by running water be obtained from the following detailed description which is to be read in connection with the accompanying drawings illustrating a present In the drawings.

Fig. 1 is a plan view of the invention mounted 5 in a water tank disposed adjacent a truck mixer;

Fig. 2 is a side elevation thereof;

Fig. 3 is a plan view of the weir chamber;

Fig. 4 is an elevation thereof and Fig. 5 is a transverse sectional view therein through along the line VV of Fig. 3.

Referring now in detail to the drawings,- a water storage tank i0 is supported on a framework II, of any suitable character, in a position adjacent a truck mounted mixer, a portion of 15 which is indicated at l2. The top of the tank is provided with a filling opening l3 and a discharge outlet IA. The outlet is provided with a valve l5 from which a connection It extends into the mixer l2. A branch connection from 20 the valve provides a capped blowout connection i A slide rod I8 is mounted vertically in the tank l0 in a position substantially centrally thereof. The upper end of the rod I8 is seated 27, in a recess in a cap l9 secured to a plate 20 removably attachedto the top of the tank. The lower end of the rod is seated in a hole in a plate attached to the bottom of the tank.

A weir chamber 2i shown more clearly in Figs. 30 3 through 5 is bored, as at 22, so as to be slidable on the rod IS. The chamber 2i has a weir 23 extending upwardly therefrom. The chamber has ports 24 and 25 extending therefrom on opposite sides of the weir. Bosses 26 are tapped 3r,

for trunnion bolts. The top wall of the chamber is provided with a. vent 21.

As shown in Figs. 1 and 2, the weir chamber is slidable on the rod l8. I also provide means for reciprocating the chamber along the rod. 40 Such means include a shaft 28 extending transversely of the tank toward one side thereof, being journaled in suitable bearings carried by the tank walls. A fork 29 is secured to the shaft 28. Links 30 are pivoted to the prongs of the fork 45 and to trunnion bolts 3! threaded in the bosses 28. The shaft 28 extends through one wall of the tank, and the protruding end is provided with a lever 32. The tank carries an arcuate guide I! for the lever whereby the latter may be fixed at any desired position. When the lever is pulled down, of course, the weir chamber 2! is raised simultaneously.

A hose connection 34 extends from the port 2' of the weir chamber to the discharge outlet ll.

A hose connection" extends from the port 24 of the weir chamber to the bottom of the tank, the end of the hose 3! being open.

In using the invention, the tank In is filled at the start of the trip, conveniently while the dry materials are being charged into the mixer. The valve ii, of course, is closed during these operations. When the tank and mixer have been charged, the lever 32 is adjusted to a predetermined position relative to the guide 33 and secured thereat. The truck on which the mixer and tank are mounted is then started on its journey toward the point where the concrete is to be delivered. When the truck is within a predetermined distance of its destination, the driver opens the valve l5, simultaneously starting the drive for the mixer. The precise amount of water required is thus admitted to the mixer and the concrete is fully mixed by the time it arrives at the point of delivery.

It will be understood that when the weir chamber is below the level of the water in the tank It, there is a net head of water tending to cause a flow through the hose connection 35, the chamber 2| and the hose connection 34, which head is equal to the distance between the top of the weir 23 and the mean level ofthe water in the tank. Thus, so long as the mean water level in the tank is above the top of the weir, water will flow from the outlet when the valve I5 is opened. As soon as the mean level in the tank falls below the top of the weir 23, no more water will be discharged. Siphoning is prevented because the vent 21 breaks any vacuum which might form in the line. The inertia of the water columns in the hose connections prevents any disturbance that insuring that the proper amount of water for abatch of concrete will be delivered to the dry materials, during the progress .of the mixer, even though the latter is subject to considerable vibration and shock, without completely emptying the tank. The provision of an extra tank for washout water is thus avoided.

Although I have illustrated and described but a preferred embodiment of the invention, it will be understood that changes in the practice and construction disclosed may be made without departing from the spirit oi the invention or the scope of the appended claims.

I claim:

1. Apparatus for dispensing a predetermined quantity or liquid comprising a container for the liquid, a conduit immersed in the liquid in the container, one end of the conduit being connected to a discharge port, the other end being adaptedto receive liquid from the container, said conduit including a chamber having a weir extending thereacross, and a substantially closed upper portion to prevent surface agitation of the liquid from aflecting flow o1 said liquid over the weir in the chamber, and means mounting said chamber in said container for movement to various depths therein.

2. Measuring apparatus for a liquid storage tank having a discharge outlet, said apparatus comprising aconduit connected to said outlet and having its free end immersed in the liquid, a substantially closed chamber connected in said conduit and mounted for submergence to various depths in said liquid, and a weir extending across said chamber effective to control the flow of liquid through said conduit unaffected by suriaceagitation.

3. Apparatus for delivering a predetermined amount of liquid from a storage tank comprising a substantially closed chamber movable vertically in the tank, a conduit connected to one side or the chamber and extending to a discharge port, and a conduit connected to the other side of the chamber and having its free end immersed in the liquid, and a weir extending across said chamber eilfective to control the flow of liquid through said conduit unaffected by surface agitation.

4. In a liquid measuring apparatus, a substantially closed chamber mounted for movement upwardly and downwardly in a storage tank, said chamber having a weir extending thereacross, a

connection from the chamber on one side of the 

